Deposition of Ni-P-BN(h) composite autocatalytic coatings

Preliminary experiments were performed in order to study the autocatalytic deposition of Ni-P-BN(h) composite coatings on 316L stainless steel. A simple 2(2) factorial experimental design has permitted establishment of the influence of the concentration of both BN(h) particles and dispersant in the plating solution on coatings characteristics such as: thickness, phosphorus content and the volumetric BN(h) percentage in the nickel matrix. The morphology of the coatings has been investigated with the aid of a scanning electron microscope. The tribological behavior under non-lubricated conditions has been evaluated by using pin-on-disc test, where the pin was made of AISI 52100 steel. Comparison between the sliding wear behavior and friction coefficients of electroless Ni-P and Ni-P-BN(h) composite deposits are also reported. It has been shown that electroless Ni-P-BN(h) composite coating with 35% BN(h) incorporated particles presented a wear factor, k, of 1.28x10(-6) mm(3) (Nm)(-1), which is nearly two orders of magnitude smaller than the wear factor of 1.09x10(-4) mm(3) (Nm)(-1), reported for a BN(h)-free electroless Ni-P. (C) 1998 Elsevier Science S.A. All rights reserved.